Engine starting system



Aug. 12, 1958 G. G. FoL'rz ENGINE STARTING SYSTEM Filed April 8, 1957United ENGrNn sTARrrNG SYSTEM Application April s, 1957, serial No.651,490

z Claims. cci. 12s- 179) This invention relates to the cold weatherstarting of internal combustion engines, and particularly to improvedcomponents of a hot fuel priming system wherein a supply of priming fuelis heated and supplied to the engine in conjunction with actuation ofthe engine starter.

Systems of the kind described incorporate automatic controls, and alsoare subject to a selective manne'r of operation according to whichpriming fuel may be supplied to the engine continuously orintermittently and in a heated or an unheated condition.

It is an object of the present invention to simplify the constructionand mode of operation, in systems as described, to the ends that thesystem may be more reliable in operation and less subject tomisoperation, as well as to the 'end of making the component parts ofthe system less costly of manufacture.

Another and particular object of the invention is to provide main andauxiliary starting switch controls, the latter being adapted to remainin a closed position when so adjusted until manually opened.

Other objects and structural details of the invention will appear fromthe following description when read in con nection with the accompanyingdrawing, which is a diagram of an engine starting system incorporating ahot fuel prime system in accordance with an illustrative embodiment ofthe invention.

Referring to the drawing, priming fuel is supplied by way of a pipe 1t)opening into the bottom of a tank 11. Flow out of the tank 11 is throughthe upper end thereof by way of a pipe 12 in which is interposed asolenoid operated shut-off valve 13, termed the priming solenoid. Thefuel is conducted to the tank 11 under pressure, there being in the linea boost pump (not shown) driven independently of the engine. Dependingupon whether the priming solenoid is energized or deenergized, ow out ofthe tank 11 is permitted or denied. In the energized condition, the flowis directed through the pipe 12 to the priming nozzles in the inductionsystem of the engine.

While engine priming has various purposes, a principal object thereof isto enable heated fuel to be supplied to the engine for purposes of morefacile starting under extremely cold conditions. In this connection,there is installed in the tank 11 a pair of immersion heaters 14 and 15which when energized transmit heat to the contained fuel within thetank. Also forming a part of the tank structure is a thermal switch 16which is arranged to sense the temperature of the contained fuel and toclose upon the achieving of a predetermined high value in suchtemperature, the thermal switch device being normally open.

The system provides for a direct connection through a conductor 17 withan electrical power source, as well as with an instrument cable 1,8 alsoconnected to the power source. Power from the line 17 is supplieddirectly to the heaters 14 and 15, through respective electrical relays19 and 20, the relays being located on opposite sides of the conductor17 in respective conductors 21and 22. 'Ihe tes Patent 'O ICC a te,

coil of relay 19 is connected to ground at 23 and so may be energizedindependently of the relay 20. The coils of the two relays may bebridged, however, by a switch 24 in which case the relays are energizedsiinultaneously. The switch 24 is operator controlled and -it will beunderstood that by its use, only one or both of the heaters 14 and 15may be energized, thus providing alternatively for low and high rates ofheating of the fuel in the tank 11.

Other operator controls are a primer switch 25 and a starter switch 26.The former is in a line 27 extending from the instrument cable 18 to aterminal pin F on a relay-switch assembly 28. The latter, along withthetank 11 and associated parts froms a principal component of the hot fuelprime system. A terminal pin G thereon is connected to ground at 29.Another pin D of the assembly is connected by a lead 31 to the coils ofthe heater relays 19 and 20. Pin B is connected by a lead 32 to thepriming solenoid 13, grounded at 33. Pins E and F are connected toopposite sides of the thermo-switch 16, by leads 34 and 35, while pin Cis connected by a lead 36 to a starter relay 37 and pin A is connectedto a lead 33 extending from the instrument cable 18 and in which isinterposed the starter switch 26.

Within the relay switch assembly 28 is a conductor 39 leading to theground pin G. The conductor 39 is connected to a common side of threerelays 41, 42 and 43. The opposite side of the relay 41 is connected bya lead 44 t0 a Contact 45 which is in turn permanently connected by alead 46 to the terminal pin E. The opposite side of the relay 42 isconnected by a resistor 47 and lead line 48 to a contact 49. Theopposite side of the relay 43 is directly connected by conductor 51 tothe terminal pin A. It will be understood that the so-called oppositesides of the relays 41, 42 and 43 are the high potential sides thereof,and that the supply of current thereto through the respective lines 4S,48 and 51 results in the energizing of the respective relays.

The contacts 44 and 49 are a part of a bank of contacts traversed bythree double pole, double throw switches, one of which is associatedwith and adjusted under control of a respective one of the relays 41, 42and 43. The relay 41 controls a switch comprising a pair of switchelements 52 and 53 tending normally to assume the position illustratedwherein element 52 engages contact 49 and element 53 engages a contact54 connected by a lead 55 with the terminal pin D. Energizing of therelay 41 effects simultaneous movement of the switch elements 52 and S3to alternate positions of adjustment wherein the element 52 engages acontact S6 connected by a lead 57 with the terminal pin B, and whereinthe switch element 53 engages an electrically disconnected contact 58.In similar manner, the relay 42 controls a pair of switch elements 59and A61. The latter element normally engages the aforementioned contact45 while the switch element 59 normally engages a 4contact 62 connectedby a lead 63 to the terminal pin C. ln their alternate positions ofadjustment, achieved upon energizing of the relay 42, the switchelements 59 and 61 engage electrically disconnected contacts 64 and 65.The switch controlled by relay 43 comprises switch elements 66 and 67respectively normally engaging contacts 68 and 69. The former is joinedby a lead 71 with Contact 56. The contact 69 is electricallydisconnected in the system. Upon energizing of the relay 43, the element66 assumes a position of engagement with an electrically disconnectedcontact 72, while switch element 67 engages a contact 73 connected by alead 74 with the base of switch element 61. The bases of the pair ofswitch elements 59 and 61 are electrically disconnected but the bases ofswitch elmentsl 52 and 53 are electrically connected, as by a line 75,as are the pair of elements 66 and 67, as by a line 76. Further, thepair of elements 52 and 53 is connected by a lead 77 to the bases of thepair of elements 66 and 67. Further, the latter are vconnected by aconductor 78 to the terminal pin F. Finally, the base of switch element59, of the pair of elements 59 and 61, is permanently connected by alead 79 to the lead 51 or to the high potential side of the relay 43.

In the operation of the system, therefore, closing of the primer switch25 closes a circuit through conductor 27, terminal pin F, lead 78, andthen by way of lines 76 and 77 to switch element 52 and line 4S to thehigh potential side of relay 42, energizing this relay. Also, thecircuit is closed through the switch element 66 to lead 71, contact 56and lead 57 to the terminal pin B and thence by way of conductor 32 tothe priming solenoid 13, energizing this solenoid and opening the valvefor flow of the priming fuel to the induction system of the engine.Closing of the starter switch 26' supplies current to the terminal pin Aand thence by way of conductor 51 to the high potential side of relay43, energizing this relay. Since conductor 79 is connected to conductor51, current is supplied also through the switch element 59 and lead 63to the terminal pin C, and thence by way of conductor 36 to the starterrelay 37 to effect cranking of the engine. In the case of the thermalswitch 16, it may be seen that since one lead 35 therefrom is connectedto the terminal pin F and since the other lead therefrom is connected tothe terminal pin E, the closing of the thermal switch, while the primerswitch 25 is closed, has the effect of energizing the relay 41, sincethe latter is connected to the terminal E through the conductor 44,contact 45 and lead 46.

The closing of primer switch 25 also tends to close a circuit throughthe heater relays 19 and 20 to energize the heaters 14 and 15, since therelays 19 and 20 are connected to terminal pin D which through the lead55, contact 54 and switch element 53 is normally connected through theconductor 77 which has a permanent connection as described with theterminal pin F.

Since the closing of the switches 25, 26 and 16 tend to energizerespective relays 42, 43 and 41, and since the energizing of theserelays alters the position of the double pole double throw controlswitches in the relay-switch assembly, the mode of operation of thesystem and the results achieved vary with the order in which the severalswitches are operated. For cold weather starting, when it is desirableto heat the priming fuel, the priming switch 25 rst is closed and thestarting switch 26 is closed immediately thereafter. The thermal switch16 is open at this time due to the low temperature of the fuel in tank11. The closing of primer switch 25 is effective as described to openthe priming solenoid 13 and to energize the heaters 14 and 15, and iseffective also to energize the relay 42. The latter accordinglymoves'the switch elements 59 and 61 to electrically disconnectedpositions in engagement with the contacts 64 and 65. Now, as starterswitch 26' is closed, the relay 43 is energized as before described, butcurrent is not supplied to the starter relay 37 since the switch element59 in this circuit has been shifted to an electrically disconnectedposition. Energizing of relay 43 shifts switch elements 66 and 67 totheir alternate positions wherein element 66 engages contact 72 andelement 67 engages contact 73. Upon this switch adjustment, therefore,current supply to the priming solenoid by way of switch element 66 andlead 71 is discontinued and the priming valve is closed whereby to cutoif the supply of priming fuel to the engine. Also at this time, theswitch element 67 is positioned to supply power to the switch element 61by way of line 74, but the element 61 is engaged with electricallydisconnected contact 65 so that no operation results.

While the switches 25 and 26 remain closed, the heaters 14 and 15continue in operation, warming the fuel in the tank 11, which containedfuel is prevented from moving to the engine by reason of the closedvalve 13. When the contained fuel has reached a predetermined hightemperature value, the thermal switch 16 closes. When this occurs, thereis as before noted an energizing of the relay 41 and a shifting of theswitch elements 52 and 53 to their alternate positions. Movement ofswitch element 53 from the contact 54 to the electrically disconnectedcontact 58 opens the circuit through terminal pin D to the heater relays19 and 20, which accordingly are deenergized to discontinue heating ofthe fuel. Movement of the switch element 52 from the contact 49 to thecontact 56 interrupts the supply of current to the relay 42, causingthis relay to become deenergized. Also, the circuit to the primingsolenoid 13 is re-closed, this time by way of the lead 77. The primingsolenoid thus opens and the heated priming fuel is admitted to theengine.

The deenergizing of solenoid 42 as described permits the switch elements59 and 61 controlled thereby to reassume the normal positionsillustrated. So adjusted, the switch element 59 closes the startingcircuit from conductor 51 to terminal pin C and starter relay 37. Afurther circuit is also closed at this time through relay 41 by way ofswitch element 67, lead 74 and switch element 61 engaging Contact 45.Even though the thermal switch 16 may re-open, therefore, as the heatedfuel leaves the tank 11 and is replaced by unheated fuel, the relay 41will remain energized while the primer switch 25 continues to be heldclosed. The described position of the parts is maintained until theengine starts, whereupon the starter switch 26 may be released and theprimer switch 25 released after a stable running of the engine has beenachieved.

In engine starts in which it is desired to prime without pre-heating,the starter switch 26 is closed ahead of the primer switch 25. Closingof the starter switch under these conditions results in immediateenergizing of the starter relay 37. Closing of the primer switch 25 hasthe effect, since the relay 43 has previously been energized by closingof the starter switch 26', of energizing the relay 41 through the switchelement 67, lead 74, switch element 61 and conductor 44. Closing of theprimer switch 25 tends also to close a circuit across and thereby toenergize the relay 42. With current supplied simultaneously to therelays 41 and 42, under these circumstances, the resistor 47 in the line48 to relay 42 plays the part of a time delay mechanism so that relay 41is the first to be energized. As a result, the switch elements 52 and 53controlled thereby are set to their alternate position of adjustment andthe circuit to the relay 42 is interrupted. The relay 42 is thus notenergized at this time. Adjustment of the switch element 52 closes acircuit through terminal pin B to the priming solenoid 13 causing thesolenoid to open. Adjustment of the switch element 53 out of engagementwith contact 54 opens the circuit through terminal pin D and therebythrough the heating relays so that the heaters 14 and 15 are notenergized.

Under these conditions of operation, the starter relay is continuouslyenergized until the engine begins to operate. The primer switch 25 maybe held continuously closed or it may be intermittently opened andclosed with the result of supplying priming fuel in intermittent manneras may be required.

The manual control switches 25 and 26 may conveniently be constructed ofthe pressure actuated, normally open type. Switches of this kind areclosed only when held closed and when released reassume an openposition. In order to relieve the operator of the necessity for holdingthe priming and starting switches depressed there may be providedanother set of switches 81 and S2 respectively in lines 27a and 38aparallel to the lines 27 and 38. The switches 8l and 82 are of the kindhaving alternate positions of adjustment, in each of which the switchwill remain until manually adjusted to its other position. The switches81 and 82 thus may be used as holding switches, after a primingoperation has been initiated by the switches 25 and 26, or they may beused in lieu of the switches 25 and 26.

In connection with a hot fuel priming operation, it Will be observedthat release of the starter switch after the engine has started andwhile the priming switch continues to be held closed, will result inre-energizing of the heater relays so that fuel supplied to the engineunder the continued or intermittent actuation of the priming switch isheated. The engine accordingly may warm up using heated fuel. The wiringof the relay-switch assembly is such that the engine starter and theheaters in the priming fuel tank cannot both be energized at the sametime.

What is claimed is:

1. A starting system for an internal combustion engine providing hotfuel prime components including a starting relay, a priming solenoidwhich when energized admits priming fuel to the engine, heaters forheating the fuel, a thermal switch responsive to the temperature of thefuel, a priming switch and a starting switch, and a relay-switchassembly controlling operation of the system in response to theselective closing of said priming switch and said starting switch, saidpriming switch and said starting switch being normally open and pendingto resume an open position when'released by the operator; characterizedby auxiliary priming and starting switches connected in parallelrelation to the iirst said priming and starting switches, said auxiliaryswitches being constructed to remain in closed position when so adjusteduntil manually opened.

2. A starting system for an internal combustion engine, including a mainprimer switch and a main starter switch, both assuming normally an openposition, a iirst relay energized by closing of said main primer switch,priming fuel heater control means energized by closing of said primerswitch, a priming fuel supply valve opened by closing of said mainprimer switch, a second relay energized by closing of said main starterswitch, a starter relay energized by closing of said main starterswitch, a first control switch adjusted by energizing of said rst relayto interrupt the circuit from said starter switch to said starter relay,a second control switch adjusted by energizing of Isaid second relay tointerrupt the circuit from said primer switch to said supply valvepermitting said valve to close, a thermal switch responsive to thetemperature of the priming fuel, a third relay energized by closing ofsaid thermal switch, a third control switch adjusted by said third relayto deenergize said irst relay, to interrupt the circuit to said fuelheater control means and to restore the circuit to said fuel supplyvalve, and auxiliary primer and starter switches in parallel to saidmain primer and starter switches and operable to remain in a setposition of adjustment until changed by the operator, the main saidswitches tending to assume an open position when released.

References Cited in the le of this patent UNITED STATES PATENTS TylerJune 1, 1954

